Isotretinoin (INN), a drug used to treat severe acne, has anti-inflammatory and antibacterial properties. INN may affect periodontal pathogenic bacteria, so we aimed to study the effect of INN on intraoral microbial profiles of periodontal disease and healthy periodontium. Our case-control study divided 180 subjects into six groups according to periodontal health status and INN usage as follows: healthy periodontium receiving INN (HINN; n = 30); those with generalized plaque-induced gingivitis receiving INN (GINN; n = 30); and those with stage I generalized periodontitis receiving INN (PINN; n = 30). Subjects not taking INN, were categorized in the same manner: those with a healthy periodontium (HC; n = 30); those with generalized plaque-induced gingivitis (GC; n = 30); and those with generalized periodontitis stage I (PC; n = 30). Plaque samples were collected to determine the prevalence of four periodontal pathogens (Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, and Fusobacterium nucleatum) in each study group using real-time polymerase chain reaction. Data were analyzed using IBM SPSS software, and multiple regression analysis was performed for each parameter tested in each group at a significance level of 0.05. All INN groups showed significantly lower levels of P. gingivalis, T. forsythia, and T. denticola and higher levels of F. nucleatum (p < 0.001). INN had an observable antimicrobial effect on the periodontal pathogen count in patients with plaque-induced gingivitis and chronic periodontitis. INN may have a potential additive antimicrobial value in the treatment of periodontal disease.
Keywords: isotretinoin; oral microbes; periodontal pathogens; periodontal therapy.